Wideband digital distributed communications system(s) (DCS) employing programmable digital signal processing circuit for scaling supported communications services

ABSTRACT

Wideband digital distributed communications systems (DCSs) employing reconfigurable digital signal processing circuit for scaling supported communications services are disclosed. The DCS includes a head-end unit that includes front end downlink signal processing circuit to receive and distribute downlink communications signals for communications services (i.e., communications bands) to remote units. The remote units also include front end uplink signal processing circuits to receive uplink communications signals to be distributed to the head-end unit. The front end signal processing circuits are either equipped with broadband filters, or such filters are eliminated, to allow the DCS to be scaled to pass added communications bands. The front end processing circuits include analog-to-digital conversion (ADC) circuits for converting received analog communications signals into digital communications signals so that the digital communications signals can be processed by digital signal processing circuit that can flexibly be configured and reconfigured to support the added communications bands.

BACKGROUND

The disclosure relates generally to distributed communications systems(DCS), and more particularly wideband digital DCSs employingprogrammable digital signal processing for scaling supportedcommunications services.

Wireless customers are increasingly demanding wireless communicationsservices, such as cellular communications services and Wi-Fi services.Thus, small cells, and more recently Wi-Fi services, are being deployedindoors. At the same time, some wireless customers use their wirelesscommunication devices in areas that are poorly serviced by conventionalcellular networks, such as inside certain buildings or areas where thereis little cellular coverage. One response to the intersection of thesetwo concerns has been the use of distributed antenna systems (DASs).DASs include remote antenna units (RAUs) configured to receive andtransmit communications signals to client devices within the antennarange of the RAUs. DASs can be particularly useful when deployed insidebuildings or other indoor environments where the wireless communicationdevices may not otherwise be able to effectively receive radio frequency(RF) signals from a source.

In this regard, FIG. 1 illustrates a distributed communications system(DCS) 100 that is configured to distribute communications services toremote coverage areas 102(1)-102(N), where ‘N’ is the number of remotecoverage areas. The DCS 100 in FIG. 1 is provided in the form of a DAS103. The DAS 103 can be configured to support a variety ofcommunications services that can include cellular communicationsservices, wireless communications services, such as RF identification(RFID) tracking, Wireless Fidelity (Wi-Fi), local area network (LAN),and wireless LAN (WLAN), wireless solutions (Bluetooth, Wi-Fi GlobalPositioning System (GPS) signal-based, and others) for location-basedservices, and combinations thereof, as examples. The remote coverageareas 102(1)-102(N) are created by and centered on RAUs 104(1)-104(N)connected to a centralized equipment 106 (e.g., a head-end controller, acentral unit, or a head-end unit). The centralized equipment 106 may becommunicatively coupled to a source transceiver 108, such as forexample, a base transceiver station (BTS) or a baseband unit (BBU). Inthis regard, the centralized equipment 106 receives downlinkcommunications signals 110D from the source transceiver 108 to bedistributed to the RAUs 104(1)-104(N). The downlink communicationssignals 110D can include data communications signals and/orcommunication signaling signals, as examples. The centralized equipment106 is configured with filtering circuits and/or other signal processingcircuits that are configured to support a specific number ofcommunications services (i.e., frequency communications bands). The RAUs104(1)-104(N) are configured to receive the downlink communicationssignals 110D from the centralized equipment 106 over a communicationslink 112 to be distributed to the respective remote coverage areas102(1)-102(N) of the RAUs 104(1)-104(N). The RAUs 104(1)-104(N) are alsoconfigured with filters and other signal processing circuits that areconfigured to support all or a subset of the specific communicationsservices (i.e., frequency communications bands) supported by thecentralized equipment 106. In a non-limiting example, the communicationslink 112 may be a wired communications link, a wireless communicationslink, or an optical fiber-based communications link. Each of the RAUs104(1)-104(N) may include an RF transmitter/receiver (not shown) and arespective antenna 114(1)-114(N) operably connected to the RFtransmitter/receiver to wirelessly distribute the communicationsservices to user equipment (UE) 116 within the respective remotecoverage areas 102(1)-102(N). The RAUs 104(1)-104(N) are also configuredto receive uplink communications signals 110U from the UE 116 in therespective remote coverage areas 102(1)-102(N) to be distributed to thesource transceiver 108.

Even though a DCS, such as the DAS 103 in FIG. 1, can address the issueof wireless customers using their wireless communication devices inareas that are poorly serviced by conventional cellular networks, DCSsare still not commonly deployed in buildings. Lack of appropriatein-building infrastructure coupled with the often prohibitively highinstallation and maintenance costs associated with a DCS means that manybuildings still remain without adequate wireless communications servicecoverage. The issues of indoor network infrastructure cost andcomplexity are further compounded by the growth of new mobiletechnologies. For example, when a DCS is deployed as an in-buildingsolution, the equipment in the DCS is configured with filters and othersignal processing circuitry configured to support specificcommunications services and technologies (e.g., 2G, 3G, Wi-Fi, etc.).Thus, additional equipment that includes filtering circuits and/or othersignal processing circuitry must be added for the DCS to support newcommunications services (i.e., new communications bands). Even morechallenging is the fact that the addition of new communications servicesto a DCS may require modification to a network infrastructure and/or theinstallation of new equipment in the DCS.

Therefore, it is desired to provide a lower cost, in-building networkingsolution that enables the flexible addition of new communicationsservices and/or modified communications services, including wirelesscommunications services, to an existing installed DCS without unduetampering with the equipment of the installed DCS.

No admission is made that any reference cited herein constitutes priorart. Applicant expressly reserves the right to challenge the accuracyand pertinency of any cited documents.

SUMMARY

Embodiments of the disclosure relate to wideband digital distributedcommunications systems (DCSs) employing a programmable digital signalprocessing circuit for scaling supported communications services. In oneexemplary aspect, a DCS is provided. The DCS includes a head-end unitthat includes an analog front end signal processing circuit configuredto receive analog downlink communications signals from one or morenetworks to support communications services (i.e., communicationsbands). The head-end unit is configured to distribute the analogdownlink communications signals over downlink communication links to aplurality of remote units to be distributed to client devices. Theremote units also include an analog front end signal processing circuitconfigured to receive analog uplink communications signals from theclient devices to be distributed over uplink communication links to thehead-end unit and back to the networks. The ability of the DCS to beflexibly scaled to support new analog communications bands and relatedcommunications services depends on analog front end signal processingcircuits in the head-end unit and the remote units for processing thereceived analog communications signals. In this regard, in aspectsdisclosed herein, the front end signal processing circuit in thehead-end unit and/or the remote units are either equipped with broadbandfilters, or such filters are eliminated to allow the DCS to be flexiblyscalable to pass added communications bands. The analog front endprocessing circuit of the head-end unit and/or the remote units includean analog-to-digital conversion (ADC) circuit for converting receivedanalog communications signals into digital communications signals sothat the digital communications signals can be processed by aprogrammable digital signal processing circuit. The programmable digitalsignal processing circuit can flexibly be programmed and reconfigured,such as through software, to support signal processing functions (e.g.,frequency conversion and filtering) for communications bands of thedigitally converted analog communications signals. In this manner, theDCS can be easily programmed and reconfigured to support different andemerging communications services.

However, interference signals that may otherwise be rejected withnarrower band filters may be passed by the front end signal processingcircuit as a result of providing broadband filters or eliminatingfilters in the front end downlink signal processing circuitry, therebyreducing the dynamic range of the distributed communications signals.Thus, in embodiments disclosed herein, to prevent the reduction and/orrestore the dynamic range of the communications signals, the ADC circuitin the front end processing circuit is configured to oversample thereceived analog communication signals for conversion into the digitalcommunications signals. Oversampling eases the requirements on thefiltering which may precede the ADC circuit. Providing a higheroversampling rate moves image frequencies for the communicationsservices higher, thereby allowing a less complex lower cost filter witha wider transition band. Further, there is an increase in thesignal-to-interference ratio (SIR) within the signal bandwidth becauseof the process gain. Thus, the digital communications signals can befiltered to reduce or eliminate the interference signals to restore thedynamic range of the communications signals. The digital signalprocessing circuit can also be configured to downsample (i.e., decimate)the digital communications signals to reduce or offset the increased bitresolution as a result of oversampling by the ADC circuit to control thetransmission bit rate of the digital communications signals. In thismanner, the required capacity of the communications links to distributethe digital communications signals can be reduced from the requiredcapacity if decimation processing were not performed to reduce orcontrol costs of the DCS when new communications services are added.

An additional embodiment of the disclosure relates to a signaldistribution unit in a wideband digital wireless distribution system(WDS). The signal distribution unit comprises a transmission analoginput communications interface coupled to a transmission communicationspath. The transmission analog input communications interface isconfigured to receive, from an analog radio frequency (RF) signalsource, a transmission analog RF communications signal having acommunications bandwidth for a communications service. The transmissioncommunications path is configured to receive the transmission analog RFcommunications signal from the transmission analog input communicationsinterface. The transmission communications path comprises a transmissionanalog-to-digital conversion (ADC) circuit configured to oversample areceived transmission analog RF communications signal at a programmedtransmission oversampling rate of at least twice the highest frequencyin the communications bandwidth to generate a transmission digital RFcommunications signal representing a digitized form of the transmissionanalog RF communications signal. The transmission communications pathalso comprises a transmission programmable digital signal processingcircuit. The transmission programmable digital signal processing circuitcomprises a transmission digital filter circuit configured to digitallyfilter the transmission digital RF communication signals in a programmedtransmission passband into a transmission filtered digital RFcommunications signal. The transmission programmable digital signalprocessing circuit also comprises a transmission digital downsamplingcircuit configured to downsample the transmission filtered digital RFcommunications signals at a programmed transmission downsample ratebased on (e.g., equal to) the programmed transmission oversampling rateto generate a transmission downsampled digital RF communications signal.The signal distribution unit also comprises a transmission digitaloutput communications interface coupled to the transmissioncommunications path and at least one transmission communications linkcoupled to at least one signal receiver unit in the WDS. Thetransmission digital output communications interface is configured todistribute the transmission downsampled digital RF communications signalover the at least one transmission communications link to the at leastone signal receiver unit.

An additional embodiment of the disclosure relates to a method ofdistributing an analog RF communications signal in a WDS. The methodcomprises receiving from an analog RF signal source, a transmissionanalog RF communications signal having a communications bandwidth for acommunications service on a transmission communications path. The methodalso comprises oversampling the received transmission analog RFcommunications signal in the transmission communications path at aprogrammed transmission oversampling rate of at least twice the highestfrequency in the communications bandwidth to generate a transmissiondigital RF communications signal representing a digitized form of thetransmission analog RF communications signal. The method also comprisesdigitally filtering the transmission digital RF communications signal inthe transmission communications path in a programmed transmissionpassband into a transmission filtered digital RF communications signal.The method also comprises downsampling the transmission filtered digitalRF communications signals in the transmission communications path at aprogrammed transmission downsample rate based on (e.g., equal to) theprogrammed transmission oversampling rate to generate a transmissiondownsampled digital RF communications signal. The method also comprisesdistributing the transmission downsampled digital RF communicationssignal from the transmission communications path over at least onetransmission communications link to the at least one signal receiverunit.

An additional embodiment of the disclosure relates to a WDS. The WDScomprises a head-end unit. The head-end unit comprises a head-enddownlink analog input communications interface coupled to a head-enddownlink communications path, the head-end downlink analog inputcommunications interface configured to receive, from an analog RF signalsource, a downlink analog RF communications signal having acommunications bandwidth for a communications service. The head-enddownlink communications path comprises a head-end downlink ADC circuitconfigured to oversample a received downlink analog RF communicationssignal at a programmed transmission oversampling rate of at least twicethe highest frequency in the communications bandwidth to generate adownlink digital RF communications signal representing a digitized formof the downlink analog RF communications signal. The head-end downlinkcommunications path also comprises a head-end transmission programmabledigital signal processing circuit. The head-end transmissionprogrammable digital signal processing circuit comprises a head-enddownlink digital filter circuit configured to digitally filter thedownlink digital RF communications signals in a programmed transmissionpassband into a downlink filtered digital RF communications signal. Thehead-end transmission programmable digital signal processing circuitalso comprises a head-end downlink digital downsampling circuitconfigured to downsample the downlink filtered digital RF communicationssignals at a programmed transmission downsample rate based on (e.g.,equal to) the programmed transmission oversampling rate to generate adownlink downsampled digital RF communications signal. The head-end unitalso comprises a head-end downlink digital output communicationsinterface coupled to the head-end downlink communications path and atleast one transmission communications link coupled to at least onesignal receiver unit in the WDS. The head-end downlink digital outputcommunications interface is configured to distribute the downlinkdownsampled digital RF communications signal over the at least onedownlink communications link to at least one remote antenna unit among aplurality of remote antenna units.

The at least one remote antenna unit among the plurality of remoteantenna units comprises a remote downlink digital input communicationsinterface coupled to a remote downlink digital communications path. Theremote downlink digital input communications interface is configured toreceive, from the at least one downlink communications link, thedownlink downsampled digital RF communications signal. The remotedownlink digital communications path comprises a remote downlinkprogrammable digital signal processing circuit. The remote downlinkprogrammable digital signal processing circuit comprises a remotedownlink digital upsampling circuit configured to upsample the receiveddownlink digital RF communications signals at a programmed receptionupsample rate based on (e.g., equal to) the programmed transmissiondownsample rate to generate a downlink upsampled digital RFcommunications signal. The remote downlink programmable digital signalprocessing circuit also comprises a remote downlink digital filtercircuit configured to digitally filter the downlink upsampled digital RFcommunication signals in a programmed reception passband into a downlinkfiltered upsampled digital RF communications signal. The remote downlinkdigital communications path also comprises a remote downlinkdigital-to-analog conversion (DAC) circuit. The remote downlink DACcircuit is configured to convert the downlink filtered upsampled digitalRF communications signal into the downlink analog RF communicationssignal representing an analog form of the downlink filtered upsampleddigital RF communications signal. The remote downlink digitalcommunications path also comprises a remote downlink analog outputcommunications interface configured to distribute the downlink analog RFcommunications signal to a client device.

Additional features and advantages will be set forth in the detaileddescription which follows and, in part, will be readily apparent tothose skilled in the art from the description or recognized bypracticing the embodiments as described in the written description andclaims hereof, as well as the appended drawings.

It is to be understood that both the foregoing general description andthe following detailed description are merely exemplary and are intendedto provide an overview or framework to understand the nature andcharacter of the claims.

The accompanying drawings are included to provide a furtherunderstanding of the disclosure, and are incorporated in and constitutea part of this specification. The drawings illustrate one or moreembodiment(s), and together with the description serve to explainprinciples and operation of the various embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of an exemplary distributed communicationssystem (DC S);

FIG. 2 is a schematic diagram of an exemplary DCS that includes frontend processing circuits configured with narrower band filtering to passcommunications bands for communications services;

FIG. 3 is a schematic diagram of a wideband digital DCS employing aprogrammable digital processing signal circuit in a head-end unit andremote units for allowing the scaling of the DCS to support existing andnew communications bands for existing and new communications services;

FIG. 4 is a flowchart illustrating an exemplary process of a signaldistribution unit in the form of a head-end unit in the wideband digitalDCS in FIG. 3 processing received analog downlink communications signalsto be distributed to remote units as signal receiver units;

FIG. 5A is a schematic diagram illustrating more detail of the head-endunit in the wideband digital DCS of FIG. 3 employing a programmabledigital processing signal circuit for allowing the scaling of the DCS tosupport existing and new communications bands for existing and newcommunications services;

FIG. 5B is a schematic diagram illustrating more detail of a remoteantenna unit (RAU) that can be employed in the wideband digital DCS ofFIG. 3 employing a programmable digital processing signal circuit forallowing the scaling of the DCS to support existing and newcommunications bands for existing and new communications services;

FIG. 6 is a flowchart illustrating an exemplary process of a signalreception unit in the form of a RAU in the wideband digital DCS in FIG.3 processing received digital RF communications signals from a head-endunit to be distributed to client devices;

FIG. 7 is a chart illustrating an exemplary performance of a 5-bitresolution wideband digital DCS that reduces interference by configuringan analog-to-digital conversion (ADC) circuit to a 6-times oversamplerate combined with digital filtering and decimation to restore dynamicrange with a reduced bit transmission rate;

FIG. 8 is a table illustrating an exemplary comparison ofsignal-to-interference (SIR) power ratio, A/D sampling rate, and bittransmission rate between a 6-bit resolution wideband digital DCS, and a5-bit resolution wideband digital DCS with ADC circuit configured to a6-times oversample rate combined with digital filtering and decimationto restore dynamic range with a reduced bit transmission rate;

FIGS. 9A and 9B are schematic diagrams of another exemplary widebanddigital DCS employing a head-end unit and remote units with programmabledigital processing signal circuit for scaling supported communicationsservices and digital baseband communications services;

FIG. 10 is a partially schematic cut-away diagram of an exemplarybuilding infrastructure in which a DCS, including but not limited to theDCSs in FIGS. 3, 5A-5B and 9A-9B can be provided, wherein unlicensedcommunications signal paths in the remote units are configured to bedisabled or disconnected to disable distribution of unlicensedcommunications signals based on monitored communications signal activityin unlicensed spectrum on the unlicensed communications signal path(s)in the remote units; and

FIG. 11 is a schematic diagram of a generalized representation of anexemplary controller that can be included in any head-end unit or remoteunit in a DCS, wherein the controller is configured to reprogram thedigital processing signal circuit in a head-end unit and/or a remoteunit to reconfigure the central and/or the remote unit for scalingsupported communications services, wherein the exemplary computer systemis adapted to execute instructions from an exemplary computer readablelink.

DETAILED DESCRIPTION

Embodiments of the disclosure relate to wideband digital distributedcommunications systems (DCSs) employing a programmable digital signalprocessing circuit for scaling supported communications services. Inaspects disclosed herein, the front end signal processing circuits areeither equipped with broadband filters, or such filters are eliminatedto allow the DCS to be flexibly scalable to pass added communicationsbands. Thus, the DCS can be configured to be flexibly scaled to supportnew/emerging analog communications bands and related communicationsservices. However, interference signals that may otherwise be rejectedwith narrower band filters may be passed by the front end signalprocessing circuits, thereby reducing the dynamic range of thedistributed communications signals. Thus, in embodiments disclosedherein, to prevent the reduction and/or restore the dynamic range of thecommunications signals, an ADC circuit in the front end processingcircuits is configured to oversample the received analog communicationsignals for conversion into the digital communications signals. Thedigital communications signals can be filtered to reduce or eliminatethe interference signals to restore the dynamic range of thecommunications signals. The digital signal processing circuit can alsobe configured to downsample (i.e., decimate) the digital communicationssignals to reduce or offset the increased bit resolution as a result ofoversampling by the ADC circuit to control the transmission bit rate ofthe digital communications signals. In this manner, the requiredcapacity of the communications links to distribute the digitalcommunications signals can be reduced from the required capacity ifdecimation processing were not performed to reduce or control costs ofthe DCS when new communications services are added.

Example DCSs employing a programmable digital signal processing circuitfor scaling supported communications services are discussed starting atFIG. 3, FIG. 2 is first discussed to illustrate expanding existingcommunications services supported by a DCS to include futurecommunications services. FIG. 2 is a schematic diagram of an exemplaryDCS 200 that includes a head-end unit (HEU) 202 communicatively coupledto a plurality of remote antenna units (RAUs) 204(1)-204(N). The HEU 202is configured to receive analog downlink communication signals206D(1)-206D(3) for existing communications services in respectivecommunication bands 208(1)-208(3) from a capacity source 210. The HEU202 is configured to distribute the received downlink communicationsignals 206D(1)-206D(3) over a downlink communications link 212D(1) to afirst RAU 204(1). The HEU 202 includes signal processing circuits216(1)-216(3) that include narrow band filters each configured to pass arespective communication band 208(1)-208(3) while rejecting signals,such as interference signals, outside of the respective communicationbands 208(1)-208(3). The first RAU 204(1) receives the downlinkcommunication signals 206D(1)-206D(3) over the downlink communicationslink 212D(1) and passes the downlink communication signals206D(1)-206D(3) to three (3) remote signal processing circuits218(1)-218(3) in this example. The signal processing circuits218(1)-218(3) include narrow band filters configured to pass arespective communication band 208(1)-208(3). The first RAU 204(1) isconfigured to wirelessly transmit the downlink communication signals206D(1)-206D(3) through one or more antennas 220(1) (220(2)-220(N) forthe other RAUs 204(2)-204(N)).

It may be desired to expand the communication services supported by theDCS 200 beyond the communications services in three (3) communicationbands 208(1)-208(3). For example, it may be desired to expandcommunication services supported by the DCS 200 to communicationsservices communication bands 208(4)-208(S), wherein ‘S’ is the number ofcommunications services supported. However, signal processing circuits216(1)-216(3) in the HEU 202 are only configured to pass communicationbands 208(1)-208(3). Thus, additional signal processing circuits wouldhave to be added to the HEU 202 to support new communication bands208(4)-208(S) for new communications services. Further, a RAU, such asRAU 204(N) shown in FIG. 2, would have to be configured with signalprocessing circuits 218(4)-218(S) to support the new communication bands208(4)-208(S) at extra expense. Even more challenging is the fact thatthe addition of new communications services 208(4)-208(S) to the DCS 200may require modification to a network infrastructure and/or theinstallation of new equipment in the DCS 200. What may be desired is toprovide a DCS that can be configured to support new communications bandsfor new communications services without necessarily requiring newequipment or modifications to existing equipment.

In this regard, FIG. 3 is a schematic diagram of a wideband digital DCS300 (“DCS 300”) that employs programmable digital processing signalcircuits in a head-end unit (HEU) 302 and remote antenna units (RAUs)304(1)-304(N) for scaling the wideband digital DCS 300 to supportexisting and new communications bands for existing and newcommunications services. The HEU 302 may be a central unit or otherprocessing circuit or system that is configured to receive transmission(e.g., downlink) analog RF communications signals 306T(1)-306T(R) fromrespective analog RF signal sources 308(1)-308(R) to be distributed overcommunications links 310(1)-310(N) to the RAUs 304(1)-304(N). Separatecommunications links could be provided for downlink and uplinkcommunications for each communications link 310(1)-310(N), or eachcommunications link 310(1)-310(N) could be configured to carry bothdownlink and uplink communications. The transmission analog RFcommunications signals 306T(1)-306T(R) correspond to particularcommunications services provided by the analog RF signal sources308(1)-308(R). Each transmission analog RF communications signal306T(1)-306T(R) has a particular communications bandwidth for itscommunications service. For example, the analog RF signal sources308(1)-308(R) may be communicatively coupled to network backhauls312(1)-312(R).

With continuing reference to FIG. 3, the HEU 302 includes transmissionanalog input communications interfaces 314T(1)-314T(R) that are eachconfigured to receive a respective transmission analog RF communicationssignal 306T(1)-306T(R) into a respective transmission communicationspath 316T(1)-316T(R). A transmission analog-to-digital conversion (ADC)circuit 318(1)-318(R) is provided in each respective transmissioncommunications path 316T(1)-316T(R) to oversample a respective receivedtransmission analog RF communications signal 306T(1)-306T(R) at adefined oversampling rate. For example, the transmission oversamplingrate may be configured to be at least twice the highest frequency in thecommunications band of the respective transmission analog RFcommunications signal 306T(1)-306T(R) within the communicationsbandwidth to generate a respective transmission digital RFcommunications signal 320T(1)-320T(R) representing a digitized form ofthe transmission analog RF communications signal 306T(1)-306T(R).Oversampling can ease the requirements on filtering which may beemployed and precede the transmission ADC circuit 318(1)-318(R). Thehigh oversampling rate moves the image frequencies higher, therebyallowing a less complex, lower cost filter with a wider transition band.Also, there is an increase in the signal-to-interference ratio (SIR)within the signal bandwidth in the generated transmission digital RFcommunications signal 320T(1)-320T(R) because of the process gain. Inthis manner, the HEU 302 may be more easily adapted to adding futurecommunication services, because the filtering passband that is includedin the HEU 302 that precedes the transmission ADC circuits 318(1)-318(R)can be relaxed or the front end filtering can be eliminated altogether.Interference signals that are passed by HEU 302 as a result of providingbroadband filters or eliminating filters can then be more easilyfiltered without decreasing the SIR. This allows for the HEU 302 to moreeasily support additional future communications services, such as thetransmission analog RF communication signal 306T(R+1)-306T(S) shown inFIG. 3, without necessarily having to add new front end processingcircuits that include narrower passbands particular to the futurecommunications services to the HEU 302. For example, interferencesignals can come from external sources such as macrocells.

With continuing reference to FIG. 3, after the transmission analog RFcommunications signals 306T(1)-306T(R) are converted by the transmissionADC circuits 318(1)-318(R) to the transmission digital RF communicationssignals 320T(1)-320T(R), the transmission digital RF communicationssignals 320T(1)-320T(R) can be filtered and further processed. In thisregard, a transmission programmable digital signal processing circuit322T(1)-322T(R) is provided in each respective transmissioncommunications path 316T(1)-316T(R). The transmission programmabledigital signal processing circuit 322T(1)-322T(R) can be configured todigitally filter the transmission digital RF communications signal320T(1)-320T(R) in a programmed transmission passband into atransmission filtered digital RF communications signals 324T(1)-324T(R).The programmed transmission passband may be stored in a transmissionpassband entry 326 in memory 328 such that the transmission programmabledigital signal processing circuit 322T(1)-322T(R) can access the memory328 to provide the digital filter passband settings. In this manner, thetransmission programmable digital signal processing circuit322T(1)-322T(R) can be reconfigured without the need for new circuits orhardware to be added to the HEU 302 to provide the desired digitalfilter passband settings based on the communication services to besupported by the wideband digital DCS 300.

While oversampling the transmission analog RF communications signal306T(1)-306T(R) in the ADC circuits 318(1)-318(R) allows for easierdigital filtering in the transmission programmable digital signalprocessing circuit 322T(1)-322T(R) with a higher SIR, the bit rate ofthe transmission digital RF communications signal 320T(1)-320T(R) isincreased as a result. This is because more samples of the transmissionanalog RF communications signal 306T(1)-306T(R) are taken by the ADCcircuits 318(1)-318(R) over a given period of time. This would increasethe bit transmission rate of the transmission digital RF communicationssignal 320T(1)-320T(R) over the communications links 310(1)-310(N) tothe RAUs 304(1)-304(N). This may increase the cost of the widebanddigital DCS 300 by having to increase the bit rate transmission capacityand/or be an overlimiting factor in the number of communication servicesthat can be supported. Thus, in the HEU 302 in FIG. 3, the transmissionprogrammable digital signal processing circuits 322T(1)-322T(R) in thisexample are additionally configured to downsample (i.e., decimate) thetransmission filtered digital RF communications signals 324T(1)-324T(R)to reduce or offset the increased bit resolution as a result ofoversampling by the transmission ADC circuits 318(1)-318(R) to controlthe transmission bit rate. In this manner, the required capacity of thecommunications links 310(1)-310(N) to distribute the digitalcommunications signals can be reduced from the required capacity ifdecimation processing were not performed to reduce or control costs ofthe wideband digital DCS 300 when new communications services are added.Or, for the same capacity of the communications links 310(1)-310(N), agreater number of communications services can be supported by thewideband digital DCS 300. In this example, the transmission programmabledigital signal processing circuits 322T(1)-322T(R) are configured todownsample the transmission filtered digital RF communications signals324T(1)-324T(R) at a programmed transmission downsample rate stored in aprogrammed transmission downsample entry 330 to generate respectivetransmission downsampled digital RF communications signals332T(1)-332T(R). A transmission digital output communications interface334T coupled to the transmission communications path and communicationslinks 310(1)-310(N) is configured to distribute the transmissiondownsampled digital RF communications signals 332T(1)-332T(R) over thecommunications links 310(1)-310(N) to the RAUs 304(1)-304(N) acting assignal receiver units.

FIG. 4 is a flowchart illustrating an exemplary process 400 of the HEU302 as a signal distribution unit in the wideband digital DCS 300 inFIG. 3 processing received transmission analog RF communications signals306T(1)-306T(R). The first step is receiving from the analog signalsource 308(1)-308(R), the transmission analog RF communications signal306T(1)-306T(R) having a communications bandwidth for a communicationsservice on a transmission communications path 316T(1)-316T(R) (block402). The next step involves the ADC circuits 318(1)-318(R) oversamplingthe received transmission analog RF communication signals306T(1)-306T(R) in the transmission communications path 316T(1)-316T(R)at a programmed transmission oversampling rate of at least twice thehighest frequency in the communications bandwidth to generate atransmission digital RF communications signal 320T(1)-320T(R)representing a digitized form of the transmission analog RFcommunications signal 306T(1)-306T(R) (block 404). The next stepinvolves a transmission programmable digital signal processing circuit322T(1)-322T(R) digitally filtering the transmission digital RFcommunications signal 320T(1)-320T(R) in the transmission communicationspath 316T(1)-316T(R) in a programmed transmission passband into atransmission filtered digital RF communications signal 324T(1)-324T(R)(block 406). The next step involves the transmission programmabledigital signal processing circuit 322T(1)-322T(R) downsampling thetransmission filtered digital RF communications signals 324T(1)-324T(R)in the transmission communications path 316T(1)-316T(R) at a programmedtransmission downsample rate based on the programmed transmissionoversampling rate to generate a transmission downsampled digital RFcommunications signal 332T(1)-332T(R) (block 408). It may be common inone non-limiting example for the programmed reception downsample rate tobe equal or approximately equal to the programmed reception upsamplerate. The next step involves distributing the transmission downsampleddigital RF communications signal 332T(1)-332T(R) from the transmissioncommunications path 316T(1)-316T(R) over at least one transmissioncommunications link 310(1)-310(N) to the RAUs 304(1)-304(N) (block 410).

Further, with reference back to FIG. 3, the RAUs 304(1)-304(N) areconfigured to wirelessly receive transmission analog RF communicationssignals 335T(1)-335T(N) (e.g., uplink RF communications signals) overrespective antennas 336(1)-336(N) from client devices. The RAUs304(1)-304(N) are also configured to distribute the receivedtransmission analog RF communications signals 335T(1)-335T(N) astransmission signal units over the communications links 310(1)-310(N) tothe HEU 302 to be distributed on the network backhauls 312(1)-312(R). Inthis regard, both the HEU 302 and the RAUs 304(1)-304(N) in the widebanddigital DCS 300 in FIG. 3 are signal distribution units. As will bediscussed in more detail below, the RAUs 304(1)-304(N) may also includeADC circuits and digital signal processing circuits for programmablyoversampling, filtering, and downsampling the received transmissionanalog RF communications signals 335T(1)-335T(N) to generate downsampleddigital RF communications signals 338T(1)-338T(N) to be distributed tothe HEU 302. This also allows the RAUs 304(1)-304(N) to more easilysupport new communication services while reducing the bit ratetransmission of signals from the RAUs 304(1)-304(N) to the HEU 302. Inthis regard, the process in FIG. 4 can also be employed by the RAUs304(1)-304(N) acting as a signal distribution unit in the widebanddigital DCS 300 in FIG. 3 to process received transmission analog RFcommunications signals 335T(1)-335T(N) to generate the downsampleddigital RF communications signals 338T(1)-338T(N) to be distributed tothe HEU 302.

As will also be discussed in more detail below, the HEU 302 and the RAUs304(1)-304(N) are also signal reception units in that they receive therespective downsampled digital RF communications signals332T(1)-332T(R), 338T(1)-338T(N) respectively, from the RAUs304(1)-304(N) and the HEU 302. As will be also discussed in more detailbelow, as signal reception units, the HEU 302 and the RAUs 304(1)-304(N)are configured to upsample the respective downsampled digital RFcommunications signals 338T(1)-338T(N), 332T(1)-332T(R) and convert suchsignals back into reception analog RF communications signals340R(1)-340R(N), 342R(1)-342R(R) to be distributed to the analog RFsignal sources 308(1)-308(R) and the antennas 336(1)-336(N) to clientdevices, respectively.

FIG. 5A is a schematic diagram illustrating more detail of the HEU 302in the wideband digital DCS 300 of FIG. 3. The transmitter (T) side(i.e., downlink) of the HEU 302 is shown in the upper portion of FIG.5A. The receiver (R) side (i.e., uplink) of the HEU 302 is shown in thelower portion of FIG. 5A. As previously discussed with regard to thewideband digital DCS 300 in FIG. 3, the transmitter side of the HEU 302includes the transmission analog input communications interfaces314T(1)-314T(R) in respective transmission communications paths316T(1)-316T(R) for receiving the transmission analog RF communicationssignals 306T(1)-306T(R) from the analog RF signal sources 308(1)-308(R).In this example, the transmission analog input communications interfaces314T(1)-314T(R) each include a transmission analog front end processingcircuit 342T(1)-342T(R). The transmission analog front end processingcircuits 342T(1)-342T(R) may include a front end filtering circuit,which may be a wideband filter circuit, configured to filter thereceived transmission analog RF communications signal 306T(1)-306T(R)into a transmission filtered analog RF communications signal306T′(1)-306T′(R). Alternatively, the transmission analog front endprocessing circuits 342T(1)-342T(R) may not include any filtering of thetransmission analog RF communications signal 306T(1)-306T(R). Thetransmission ADC circuits 318(1)-318(R) are configured to oversample thereceived transmission filtered analog RF communications signals306T′(1)-306T′(R) at the programmed transmission oversampling rate togenerate the transmission digital RF communications signals320T(1)-320T(R) representing the digitized form of the transmissionfiltered analog RF communications signals 306T′(1)-306T′(R).

With continuing reference to FIG. 5A, the transmission communicationspaths 316T(1)-316T(R) also include the transmission programmable digitalsignal processing circuits 322T(1)-322T(R). The transmissionprogrammable digital signal processing circuits 322T(1)-322T(R) eachinclude optional transmission digital downlink conversion (DDC) circuits344T(1)-344T(R) each configured to downconvert the frequency of thetransmission digital RF communications signals 320T(1)-320T(R) intotransmission baseband (e.g., I/Q) digital RF communications signals346T(1)-346T(R). For example, the transmission baseband (e.g., I/Q)digital RF communications signals 346T(1)-346T(R) may be communicatedaccording to the common public radio interface (CPRI) protocol as anexample. The transmission baseband digital RF communications signals346T(1)-346T(R) are then digitally filtered by transmission digitalfilter circuits 348T(1)-348T(R) in a programmed transmission passbandinto the transmission filtered baseband digital RF communicationssignals 350T(1)-350T(R). As previously discussed, the programmedtransmission passband rate may be stored in the transmission passbandentry 326 in the memory 328. A controller circuit 352 is provided thatis configured to read the programmed transmission passband rate in thetransmission passband entry 326 from memory 328 and configure thetransmission digital filter circuits 348T(1)-348T(R) to filter thetransmission baseband digital RF communications signals 346T(1)-346T(R)in the programmed, desired transmission passbands. In this manner, thetransmission digital filter circuits 348T(1)-348T(R) in the transmissionprogrammable digital signal processing circuits 322T(1)-322T(R) can beconfigured and reconfigured to pass any desired transmission passbandsto provide for expansion and reconfiguration of supported communicationsservices. A user interface 353 may be provided in the HEU 302 thatallows a user or other system to direct the controller circuit 352 toprogram the desired transmission passband rate in memory 328 for use bytransmission programmable digital signal processing circuits322T(1)-322T(R) in digitally filtering the transmission baseband digitalRF communications signals 346T(1)-346T(R).

With continuing reference to FIG. 5A, transmission digital downsamplingcircuits 354T(1)-354T(R) are also provided in the transmissionprogrammable digital signal processing circuits 322T(1)-322T(R) todownsample the transmission filtered baseband digital RF communicationssignals 350T(1)-350T(R) at a programmed transmission downsample ratebased on (e.g., equal or substantially equal to) the programmedtransmission oversampling rate to generate the transmission downsampleddigital RF communications signals 332T(1)-332T(R). As discussed above,downsampling the transmission filtered baseband digital RFcommunications signals 350T(1)-350T(R) can reduce the bit transmissionrate of the transmission downsampled digital RF communications signals332T(1)-332T(R) communicated over the communications links 310(1)-310(N)to the RAUs 304(1)-304(N) (shown in FIG. 3). As previously discussed,the programmed transmission downsample rate may be stored in thetransmission downsample entry 330 in memory 328. The controller circuit352 is configured to read the programmed transmission downsample ratefrom the transmission downsample entry 330 in memory 328 and configuretransmission digital downsampling circuits 354T(1)-354T(R) to downsamplethe transmission filtered baseband digital RF communications signals350T(1)-350T(R) to the desired sample rate. The user interface 353 maybe configured to allow a user or other system to direct the controllercircuit 352 to program the desired transmission downsample rate inmemory 328 for use by transmission digital downsampling circuits354T(1)-354T(R) in downsampling transmission filtered baseband digitalRF communications signals 350T(1)-350T(R).

With continuing reference to FIG. 5A, the HEU 302 includes thetransmission digital output communications interface 334T configured toreceive and distribute the transmission downsampled digital RFcommunications signals 332T(1)-332T(R) over the selected communicationslinks 310(1)-310(N) to the RAUs 304(1)-304(N). The transmission digitaloutput communications interface 334T may include a switch matrix circuit356, which is a R×N matrix in this example. The switch matrix circuit356 is configured to receive the transmission downsampled digital RFcommunications signals 332T(1)-332T(R) and route the transmissiondownsampled digital RF communications signals 332T(1)-332T(R) to theRAUs 304(1)-304(N). A plurality of transmission multiplexer circuits358T(1)-358T(R) is configured to selectively route the transmissiondownsampled digital RF communications signals 332T(1)-332T(R) to thedesired communications links 310(1)-310(N) to be distributed to the RAUs304(1)-304(N).

FIG. 5A also shows the receiver (R) side of the HEU 302 for processingreceived downsampled digital RF communications signals 338T(1)-338T(N)from the RAUs 304(1)-304(N). However, the receiver (R) side of the RAU304 will next be discussed with regard to FIG. 5B to complete thediscussion of the transmission of downsampled digital RF communicationssignals 332T(1)-332T(R) to client devices.

In this regard, FIG. 5B is a schematic diagram illustrating more detailof a RAU 304 using RAU 304(1) as an example employed in the widebanddigital DCS 300 of FIG. 3 employing a programmable digital processingsignal circuit for allowing the scaling of the DCS to support existingand new communications bands for existing and new communicationsservices. As shown in the receiver (R) side of the RAU 304(1) in thelower portion of FIG. 5B, the transmission downsampled digital RFcommunications signals 332T(1)-332T(R) are received in the RAU 304according to the routing provided by the transmission digital outputcommunications interface 334T in the HEU 302. The RAU 304(1) includes ademutiplexer circuit 500 as part of a reception digital inputcommunications interface 502R that receives the transmission downsampleddigital RF communications signals 332T(1)-332T(R) from thecommunications link 310(1) and separates the transmission downsampleddigital RF communications signals 332T(1)-332T(R) into transmissiondownsampled digital RF communications signals (e.g., channels)504T(1)-504T(M) in a plurality of reception digital communications paths506R(1)-506R(M). The reception digital communications paths506R(1)-506R(M) each include reception programmable digital signalprocessing circuits 508R(1)-508R(M). Each reception programmable digitalsignal processing circuit 508R(1)-508R(M) includes a reception digitalupsampling circuit 510R(1)-510R(M) each configured to upsample thetransmission downsampled digital RF communications signal504T(1)-504T(M) at a programmed reception upsample rate based on theprogrammed transmission downsample rate to generate reception upsampleddigital RF communications signals 512R(1)-512R(M), because of thedownsampling performed in the HEU 302. For example, the programmedreception upsample rate and the programmed reception downsample rate canbe equal. A controller circuit 514 is provided that is configured toread the programmed reception upsample rate in a reception upsampleentry 516 from a memory 518 and configure the reception digitalupsampling circuits 510R(1)-510R(M) to upsample transmission downsampleddigital RF communications signal 504T(1)-504T(M) in the programmed,desired upsample rate. In this manner, the reception digital upsamplingcircuits 510R(1)-510R(M) in the reception programmable digital signalprocessing circuits 508R(1)-508R(M) can be configured and reconfiguredto upsample at any desired umsampling rate to provide for expansion andreconfiguration of supported communications services. A user interface520 may be provided in the RAU 304(1) that allows a user or other systemto direct the controller circuit 514 to program the reception upsamplerate in memory 518 for use by reception digital upsampling circuits510R(1)-510R(M) in upsampling transmission downsampled digital RFcommunications signal 504T(1)-504T(M).

With continuing reference to FIG. 5B, the reception programmable digitalsignal processing circuits 508R(1)-508R(M) also include a respectivereception digital filter circuit 522R(1)-522R(M). The reception digitalfilter circuits 522R(1)-522R(M) are each configured to digitally filterthe reception upsampled digital RF communications signals512R(1)-512R(M) in a programmed reception passband into receptionfiltered upsampled digital RF communications signals 524R(1)-524R(M).The controller circuit 514 is configured to read the programmedreception passband in a reception passband entry 526 from the memory 518and configure the reception digital filter circuit 522R(1)-522R(M) todigitally filter the reception upsampled digital RF communicationssignals 512R(1)-512R(M) in the programmed, desired pass band. In thismanner, the reception digital filter circuit 522R(1)-522R(M) in thereception programmable digital signal processing circuits508R(1)-508R(M) can be configured and reconfigured to upsample at anydesired filtering passband to provide for expansion and reconfigurationof supported communications services. The user interface 520 in the RAU304(1) can be configured to allow a user or other system to direct thecontroller circuit 514 to program the desired reception passband rate inmemory 518 for use by the reception digital filter circuit522R(1)-522R(M) in digitally filtering the reception upsampled digitalRF communications signals 512R(1)-512R(M).

With continuing reference to FIG. 5B, reception programmable digitalsignal processing circuits 508R(1)-508R(M) also include optionalreception digital uplink conversion (DUC) circuits 528R(1)-528R(M)configured to upconvert from baseband frequency, the frequency of thereception filtered upsampled digital RF communications signals524R(1)-524R(M) into reception digital RF communications signals530R(1)-530R(M). The frequency upconversion may be to the originalfrequency of the transmission digital RF communications signals320T(1)-320T(R) in the HEU 302 (see FIG. 5A). A receptiondigital-to-analog conversion (DAC) circuit 532R is provided that isconfigured to convert the combined reception digital RF communicationssignals 530R(1)-530R(M) into the reception analog RF communicationssignals 342R(1)-342R(R) representing an analog form of the receptiondigital RF communications signals 530R(1)-530R(M). The reception analogRF communications signals 342R(1)-342R(R) are directed to a receptionanalog output communications interface 534R that includes a receptionanalog front end processing circuit 536R. The reception analog front endprocessing circuit 536R may be configured to further process thereception analog RF communications signals 342R(1)-342R(R) to preparethe reception analog RF communications signals 342R(1)-342R(R) to betransmitted over the antenna 336(1).

FIG. 6 is a flowchart illustrating an exemplary process 600 of the RAU304 as a signal reception unit in the wideband digital DCS 300 in FIG.5B processing the received transmission downsampled digital RFcommunications signals 332T(1)-332T(R) from the HEU 302. In this regard,a first step involves the reception digital input communicationsinterface 502R receiving, from at least one communications link310(1)-310(N), the transmission downsampled digital RF communicationssignal 332T(1)-332T(R) (block 602). A next step in the process 600involves a reception digital upsampling circuit 510R(1)-510R(M)upsampling the received transmission downsampled digital RFcommunications signal 332T(1)-332T(R) at a programmed reception upsamplerate based on (e.g., equal or substantially equal to) the programmedtransmission downsample rate to generate a reception upsampled digitalRF communications signal 512R(1)-512R(M) (block 604). In a next step,the process 600 involves a reception digital filter circuit522R(1)-522R(M) digitally filtering the reception upsampled digital RFcommunications signal 512R(1)-512R(M) in a programmed reception passbandinto a reception filtered upsampled digital RF communications signal524R(1)-524R(M) (block 606). A next step in the process 600 involves areception DAC circuit 532R converting the reception filtered upsampleddigital RF communications signal 524R(1)-524R(M) into a reception analogRF communications signal 342R(1)-342R(R) representing an analog form ofthe reception filtered upsampled digital RF communications signal524R(1)-524R(M) (block 608). A next step in the process 600 theninvolves distributing the reception analog RF communications signal342R(1)-342R(R), such as to an antenna 336 to be transmitted to clientdevices (block 610). The process 600 in FIG. 6 can also be employed bythe HEU 302 acting a signal reception unit in the wideband digital DCS300 in FIG. 3 to process received downsampled digital RF communicationssignals 338T(1)-338T(N) to be distributed to the analog RF signalsources 308(1)-308(R).

FIG. 5B also illustrates more detail of transmitter (T) side of the RAU304(1) in the wideband digital DCS 300 of FIG. 3. The transmitter (T)side (i.e., uplink) of the RAU 304(1) is shown in the upper portion ofFIG. 5B. The transmitter side of the RAU 304(1) includes a transmissionanalog input communications interface 614T(1) in a transmissioncommunications path 616T for receiving the transmission analog RFcommunications signal 335T(1) from a client device over antenna 336(1).In this example, the transmission analog input communications interface614T(1) includes a transmission analog front end processing circuit642T. The transmission analog front end processing circuit 642T(1) mayinclude a front end filtering circuit, which may be a wideband filtercircuit, configured to filter the received transmission analog RFcommunications signal 335T(1) into a transmission filtered analog RFcommunications signal 335T′(1). Alternatively, the transmission analogfront end processing circuit 642T(1) may not include any filtering ofthe transmission analog RF communications signal 335T(1). A transmissionADC circuit 618(1) is configured to oversample the received transmissionfiltered analog RF communications signal 335T′(1) at the programmedtransmission oversampling rate to generate a transmission filtereddigital RF communications signal 620T(1) representing the digitized formof the transmission filtered analog RF communications signal 335T′(1). Aprogrammable digital filtering circuit 619T may also be provided tofurther filter the transmission filtered digital RF communicationssignal 620T(1) to generate transmission filtered digital RFcommunications signal 620T(1) to reduce the SIR. The passbands ofprogrammable digital filtering circuit 619T may be configured to beprogrammed by the controller circuit 514.

With continuing reference to FIG. 5B, the transmission filtered digitalRF communications signal 620T(1) is split among transmissioncommunications paths 616T(1)-616T(M) which also include the transmissionprogrammable digital signal processing circuits 622T(1)-622T(M). Thetransmission programmable digital signal processing circuits622T(1)-622T(M) each include optional transmission DDC circuits644T(1)-644T(M) each configured to downconvert the frequency of thetransmission filtered digital RF communications signal 620T(1) intotransmission baseband (e.g., I/Q) digital RF communications signals646T(1)-646T(M). The transmission baseband digital RF communicationssignals 646T(1)-646T(M) are then digitally filtered by transmissiondigital filter circuits 648T(1)-648T(M) in a programmed transmissionpassband into the transmission filtered baseband digital RFcommunications signals 650T(1)-650T(M). As previously discussed, theprogrammed transmission passband rate may be stored in the transmissionpassband entry 626 in the memory 518. The controller circuit 514 isconfigured to read the programmed transmission passband rate in thetransmission passband entry 626 from memory 518 and configure thetransmission digital filter circuits 648T(1)-648T(M) to filter thetransmission baseband digital RF communications signals 646T(1)-646T(M)in the programmed, desired transmission passbands. In this manner, thetransmission digital filter circuits 648T(1)-648T(M) in the transmissionprogrammable digital signal processing circuits 622T(1)-622T(M) can beconfigured and reconfigured to pass any desired transmission passbandsto provide for expansion and reconfiguration of supported communicationsservices. The user interface 520 allows a user or other system to directthe controller circuit 514 to program the desired transmission passbandrate in memory 518 for use by transmission programmable digital signalprocessing circuits 622T(1)-622T(M) in digitally filtering thetransmission baseband digital RF communications signals 646T(1)-646T(M).

With continuing reference to FIG. 5B, transmission digital downsamplingcircuits 654T(1)-654T(M) are also provided in the transmissionprogrammable digital signal processing circuits 622T(1)-622T(M) todownsample the transmission filtered baseband digital RF communicationssignals 650T(1)-650T(M) at a programmed transmission downsample ratebased on (e.g., equal or substantially equal to) the programmedtransmission oversampling rate to generate the transmission downsampleddigital RF communications signals 652T(1)-652T(M). As discussed above,downsampling the transmission filtered baseband digital RFcommunications signals 650T(1)-650T(M) can reduce the bit transmissionrate of the transmission downsampled digital RF communications signals652T(1)-652T(M) communicated over the communications links 310(1)-310(N)to the RAUs 304(1)-304(N). As previously discussed, the programmedtransmission downsample rate may be stored in the transmissiondownsample entry 630 in memory 518. The controller circuit 514 isconfigured to read the programmed transmission downsample rate from thetransmission downsample entry 630 in memory 518 and configuretransmission digital downsampling circuits 654T(1)-654T(M) to downsamplethe transmission filtered baseband digital RF communications signals650T(1)-650T(M) to the desired sample rate. The user interface 520 maybe configured to allow a user or other system to direct the controllercircuit 514 to program the desired transmission downsample rate inmemory 518 for use by transmission digital downsampling circuits654T(1)-654T(M) in downsampling transmission filtered baseband digitalRF communications signals 650T(1)-650T(M).

With continuing reference to FIG. 5B, the RAU 304(1) includes atransmission digital output communications interface 634T(1) configuredto receive and distribute the transmission downsampled digital RFcommunications signals 652T(1)-652T(M) over the selected communicationslinks 310(1)-310(N) to the HEU 302. The transmission digital outputcommunications interface 634T(1) may include a time-divisionalmultiplexer (TDM) circuit 656 to distribute the downsampled digital RFcommunications signals 652T(1)-652T(M) in different time slots asdownsampled digital RF communications signals 338T(1) to the HEU 302over the communications link 310(1).

The downsampled digital RF communications signals 338T(1) communicatedfrom the RAU 304(1) to the HEU 302 over communications link 310(1) andthe other downsampled digital RF communications signals 338T(2)-338T(N)from the other RAUs 304(2)-304(N) communicated over communication links310(2)-310(N), are received by the receiver (R) side of the HEU 302shown in FIG. 5A. The receiver side of the HEU 302 in FIG. 5A will nowbe discussed.

As shown in the receiver (R) side of the HEU 302 in the lower portion ofFIG. 5A, the downsampled digital RF communications signals338T(1)-338T(N) are received in the HEU 302. The HEU 302 includes ademutiplexer circuit 700 as part of a reception digital inputcommunications interface 702R that receives the downsampled digital RFcommunications signals 338T(1)-338T(N) from the communications links310(1)-310(N) and routes the downsampled digital RF communicationssignals 338T(1)-338T(N) in the reception digital output communicationinterface 334R, provided in the form of a switching matrix circuit 356in this example, into reception downsampled digital RF communicationssignals (e.g., channels) 704R(1)-704R(N) in a plurality of receptiondigital communications paths 706R(1)-706R(M). The reception digitalcommunications paths 706R(1)-706R(N) each include reception programmabledigital signal processing circuits 708R(1)-708R(N). Each receptionprogrammable digital signal processing circuit 708R(1)-708R(N) includesa reception digital upsampling circuit 710R(1)-710R(N) each configuredto upsample the reception downsampled digital RF communications signal704R(1)-704R(N) at a programmed reception upsample rate based on (e.g.,equal or substantially equal to) the programmed transmission downsamplerate to generate reception upsampled digital RF communications signals712R(1)-712R(N), because of the downsampling performed in the HEU 302. Acontroller circuit 352 is provided that is configured to read theprogrammed reception upsample rate in a reception upsample entry 716from the memory 328 and configure the reception digital upsamplingcircuits 710R(1)-710R(N) to upsample reception downsampled digital RFcommunications signals 704R(1)-704R(N) in the programmed, desiredupsample rate. In this manner, the reception digital upsampling circuits710R(1)-710R(N) in the reception programmable digital signal processingcircuits 708R(1)-708R(N) can be configured and reconfigured to upsampleat any desired upsampling rate to provide for expansion andreconfiguration of supported communications services. The user interface353 may be provided in the HEU 302 that allows a user or other system todirect the controller circuit 352 to program the reception upsample ratein memory 328 for use by reception digital upsampling circuits710R(1)-710R(N) in upsampling reception downsampled digital RFcommunications signals 704R(1)-704R(N).

With continuing reference to FIG. 5A, the reception programmable digitalsignal processing circuits 708R(1)-708R(N) also include a respectivereception digital filter circuit 722R(1)-722R(N). The reception digitalfilter circuits 722R(1)-722R(N) are each configured to digitally filterthe reception upsampled digital RF communications signals712R(1)-712R(N) in a programmed reception passband into receptionfiltered upsampled digital RF communications signals 724R(1)-724R(N).The controller circuit 352 is configured to read the programmedreception passband in a reception passband entry 726 from the memory 328and configure the reception digital filter circuits 722R(1)-722R(N) todigitally filter the reception upsampled digital RF communicationssignals 712R(1)-712R(N) in the programmed, desired passband. In thismanner, the reception digital filter circuits 722R(1)-722R(N) in thereception programmable digital signal processing circuits708R(1)-708R(N) can be configured and reconfigured to upsample at anydesired filtering passband to provide for expansion and reconfigurationof supported communications services. The user interface 353 in the HEU302 can be configured to allow a user or other system to direct thecontroller circuit 352 to program the desired reception passband rate inmemory 328 for use by the reception digital filter circuits722R(1)-722R(N) in digitally filtering the reception upsampled digitalRF communications signals 712R(1)-712R(N).

With continuing reference to FIG. 5A, reception programmable digitalsignal processing circuits 708R(1)-708R(N) also include optionalreception DUC circuits 728R(1)-728R(N) configured to upconvert frombaseband frequency, the frequency of the reception filtered upsampleddigital RF communications signals 724R(1)-724R(N) into reception digitalRF communications signals 730R(1)-730R(N). The frequency upconversionmay be to the original frequency of the transmission digital RFcommunications signals 620T(1)-620T(R) in the RAU 304(1) (see FIG. 5B).Reception DAC circuits 732R(1)-732R(N) are provided that are eachconfigured to convert the reception digital RF communications signals730R(1)-730R(N) into the reception analog RF communications signals742R(1)-742R(N) representing an analog form of the reception digital RFcommunications signals 730R(1)-730R(N). The reception analog RFcommunications signals 742R(1)-742R(N) are directed to a receptionanalog output communications interface 734R that includes receptionanalog front end processing circuits 736R(1)-736R(N). The receptionanalog front end processing circuits 736R(1)-736R(N) may be configuredto further process the reception analog RF communications signals742R(1)-742R(N) to generate the reception analog RF communicationssignals 340R(1)-340R(N) to be distributed to the analog RF signalsources 308(1)-308(R).

FIG. 7 is a chart 800 illustrating an exemplary performance of a 5-bitresolution wideband digital DCS that reduces interference by configuringan ADC circuit to a 6-times oversample rate combined with digitalfiltering and decimation to restore dynamic range with a reduced bittransmission rate. The ADC circuit could be the transmission ADC circuit318(1)-318(R) in the HEU 302 in FIG. 5A and/or the transmission ADCcircuits 618(1)-618(N) in the RAUs 304(1)-304(N), as shown intransmission ADC circuit 618(1) in the RAU 304(1) in FIG. 5B. Theefficiency of the proposed embodiments to improve the performance of aWDS in the presence of interference, and without requiring the use ofcostly high bit resolution ADC circuits is shown. The graph 800 showsthat the performance curve 802 of the 5-bit resolution system (withinterference) can be improved (i.e. EVM increased) by increasing thenumber of bits of the ADC circuit from 5 bits to 6 bits, as shown incurve 806. The results further confirm that configuring the ADC circuitto oversample by a factor of six (6) in combination with digitalfiltering and downsampling (i.e., decimation) by a factor of six (6)restores the performance of the 5-bit system to the same level ofperformance as the 6-bit system, as shown in curve 804.

FIG. 8 is a table 808 illustrating an exemplary comparison of SIR powerratio, A/D sampling rate, and bit transmission rate between a 6-bitresolution wideband digital DCS, and a 5-bit resolution wideband digitalDCS with ADC circuit configured to a 6-times oversample rate combinedwith digital filtering and decimation to restore dynamic range with areduced bit transmission rate. The sampling frequency of theconventional WDS was 650 MHz. The sampling frequency of proposed WDS was3.9 GHz. Assuming the lowest allowed SIR of a WDS afflicted by a stronginterference signal of −4.5 dB, this means that any increase in thelevel of the interfering signal would cause the performance of the WDSto fall below the required threshold. With an ADC circuit bit resolutionof five (5) bits, the physical bit rate transmission of the front-haulof this WDS was 3.25 Gb/s. One way to increase the tolerance of thesystem to stronger interference would be to use an ADC circuit with ahigher number of bits. In this case, using a 6-bit ADC circuit resultsin a higher tolerance to interference (6.5 dB more), thus allowing theWDS to meet the required performance level even with a lower SIR of −11dB. However, using a 6-bit-resolution ADC circuit results in a higherphysical bit rate transmission of the front-haul to 3.9 Gb/s (20%increase). To the contrary, using the proposed embodiments, it ispossible to restore the minimum SIR to −11 dB without increasing thephysical bit transmission rate. In this system, the carrier frequencyused was 2.4 GHz, the desired and interfering signals were OFDM signalswith 135 MHz bandwidth.

A WDS employing programmable digital signal processing circuits forscaling supported communications services, including but not limited tothe DCSs in FIGS. 3, 5A-5B, and 9A-9B, can also include a digital signalsource for distributing communications signals received already in adigitized format. Further, such WDSes can also include optical fibercommunication links to provide greater data bit rate transmissioncapacity. In this regard, FIGS. 9A and 9B are a schematic diagram ofanother exemplary HEU 902 and RAU 904 (only RAU 904(1) is shown)employing a programmable digital processing signal circuit for scalingsupported communications services and digital baseband communicationsservices. The HEU 902 and RAU 904 are similar to the HEU 302 and RAU304(1) in FIGS. 5A and 5B, and thus common components therebetween areshown with common element numbers and thus will not be re-described. Asshown in FIG. 9A, the HEU 902 includes transmission digital inputcommunications interfaces 905(1)-905(T) coupled to transmission digitalcommunications paths 916(1)-916(T). The transmission digital inputcommunications interfaces 905(1)-905(T) are configured to receive, fromdigital RF signal source 908(1)-908(T), transmission digital RFcommunications signals 906T(1)-906T(T). The digital RF signal sources908(1)-908(T) may be baseband units (BBUs) 910(1)-910(T) as an example.The digital RF signal sources 908(1)-908(T) may be coupled to networkbackhauls 912(1)-912(T). The transmission digital communications paths916(1)-916(T) include respective transceivers 920(1)-920(T) andchannelizer circuits 922(1)-922(T) to distribute the transmissiondigital RF communications signals 906T(1)-906T(T) to the RAUs904(1)-904(N), of which a generalized diagram of RAU 904 is shown inFIG. 9B. Electrical-to-optical (E-O) converters 924(1)-924(N) areprovided to convert the transmission digital RF communications signals906T(1)-906T(T) and the transmission downsampled digital RFcommunications signals 332T(1)-332T(R) to optical digital RFcommunications signals to be distributed over optical communicationslinks 310-0(1)-310-0(N). The receiver (R) side of the HEU 902 includesoptical-to-electrical (O-E) converters 926(1)-926(N) that are configuredto convert received downsampled digital RF communications signals338T(1)-338T(N) from the RAUs 904(1)-904(N) as optical digital RFcommunications signals from the RAUs 904(1)-904(N) to electricalsignals. The received optical digital RF communications signals are thesame as the digital RF communications signals described above withregard to FIG. 9A, but in optical form.

To support distribution of optical digital RF communications signals,the RAU 904(1) shown in FIG. 9B shows an E-O converter 930(1) configuredto convert downsampled digital RF communications signal 338T(1) intooptical digital RF communications signals. Further, the RAU 904(1) shownin FIG. 9B shows an O-E converter 932(1) configured to converttransmission downsampled digital RF communications signals332T(1)-332T(R) into optical digital RF communications signals. The RAU904(1) illustrated in FIG. 9B is applicable to the other RAUs904(2)-904(N) not shown.

A wideband digital DCS employing programmable digital signal processingcircuits for scaling supported communications services, including butnot limited to the DCSs in FIGS. 3, 5A-5B and 9A-9B, can be provided inan indoor environment, such as illustrated in FIG. 10. In this regard,FIG. 10 is a partially schematic cut-away diagram of a buildinginfrastructure 1000 employing a WDS 1002 employing a programmabledigital signal processing circuit for scaling supported communicationsservices. The building infrastructure 1000 in this embodiment includes afirst (ground) floor 1004(1), a second floor 1004(2), and a third floor1004(3). The floors 1004(1)-1004(3) are serviced by the central unit1006 to provide the antenna coverage areas 1008 in the buildinginfrastructure 1000. The central unit 1006 is communicatively coupled toa base station 1009 to receive downlink communications signals 1014Dfrom the base station 1009. The base station 1009 may be coupled to anoperational and support system (OSS) 110 to receive data about theperformance of remote antenna units 1012 in the WDS 1002 on a per remoteunit basis for determining WDS optimizations. The central unit 1006 iscommunicatively coupled to the remote antenna units 1012 to receiveuplink communications signals 1014U from the remote antenna units 1012,similar to as previously discussed above for other WDSs. The downlinkand uplink communications signals 1014D, 1014U communicated between thecentral unit 1006 and the remote antenna units 1012 are carried over ariser cable 1016 in this example. The riser cable 1016 may be routedthrough interconnect units (ICUs) 1018(1)-1018(3) dedicated to eachfloor 1004(1)-1004(3) that route the downlink and uplink communicationssignals 1014D, 1014U to the remote antenna units 1012 and also providepower to the remote antenna units 1012 via array cables 1020(1)-1020(6).

The supported communications services in the WDSes disclosed herein caninclude any communications bands desired. Examples of communicationservices include, but are not limited to, the US Cellular band, PersonalCommunication Services (PCS) band, Advanced Wireless Services (AWS)band, 700 MHz band, Global System for Mobile communications (GSM) 900,GSM 1800, and Universal Mobile Telecommunication System (UMTS). Thecommunications bands may include licensed US FCC and Industry Canadafrequencies (824-849 MHz on uplink and 869-894 MHz on downlink), US FCCand Industry Canada frequencies (1850-1915 MHz on uplink and 1930-1995MHz on downlink), US FCC and Industry Canada frequencies (1710-1755 MHzon uplink and 2110-2155 MHz on downlink), US FCC frequencies (698-716MHz and 776-787 MHz on uplink and 728-746 MHz on downlink), EU R & TTEfrequencies (880-915 MHz on uplink and 925-960 MHz on downlink), EU R &TTE frequencies (1710-1785 MHz on uplink and 1805-1880 MHz on downlink),EU R & TTE frequencies (1920-1980 MHz on uplink and 2110-2170 MHz ondownlink), US FCC frequencies (806-824 MHz on uplink and 851-869 MHz ondownlink), US FCC frequencies (896-901 MHz on uplink and 929-941 MHz ondownlink), US FCC frequencies (793-805 MHz on uplink and 763-775 MHz ondownlink), and US FCC frequencies (2495-2690 MHz on uplink anddownlink). Further, the WDS can be configured to support any wirelesstechnologies desired, including but not limited to Code DivisionMultiple Access (CDMA), CDMA200, 1×RTT, Evolution-Data Only (EV-DO),UMTS, High-speed Packet Access (HSPA), GSM, General Packet RadioServices (GPRS), Enhanced Data GSM Environment (EDGE), Time DivisionMultiple Access (TDMA), Long Term Evolution (LTE), iDEN, and CellularDigital Packet Data (CDPD).

FIG. 11 is a schematic diagram representation of additional detailillustrating a computer system 1100 that could be employed in acontroller circuit for configuring processing circuits in a WDSemploying programmable digital signal processing circuits for scalingsupported communications services, including but not limited to the DCS.For example, the computer system 1100 could provide the controllercircuits 352, 514 in the HEU 302 and RAU 304(1) in FIGS. 5A and 5B as anexample. In this regard, the computer system 1100 is adapted to executeinstructions from an exemplary computer-readable medium to perform theseand/or any of the functions or processing described herein.

In this regard, the computer system 1100 in FIG. 11 may include a set ofinstructions that may be executed to program and configure programmabledigital signal processing circuits in a WDS for supporting scaling ofsupported communications services. The computer system 1100 may beconnected (e.g., networked) to other machines in a LAN, an intranet, anextranet, or the Internet. While only a single device is illustrated,the term “device” shall also be taken to include any collection ofdevices that individually or jointly execute a set (or multiple sets) ofinstructions to perform any one or more of the methodologies discussedherein. The computer system 1100 may be a circuit or circuits includedin an electronic board card, such as, a printed circuit board (PCB), aserver, a personal computer, a desktop computer, a laptop computer, apersonal digital assistant (PDA), a computing pad, a mobile device, orany other device, and may represent, for example, a server or a user'scomputer.

The exemplary computer system 1100 in this embodiment includes aprocessing device or processor 1102, a main memory 1104 (e.g., read-onlymemory (ROM), flash memory, dynamic random access memory (DRAM), such assynchronous DRAM (SDRAM), etc.), and a static memory 1106 (e.g., flashmemory, static random access memory (SRAM), etc.), which may communicatewith each other via a data bus 1108. Alternatively, the processor 1102may be connected to the main memory 1104 and/or static memory 1106directly or via some other connectivity means. The processor 1102 may bea controller, and the main memory 1104 or static memory 1106 may be anytype of memory.

The processor 1102 represents one or more general-purpose processingdevices, such as a microprocessor, central processing unit, or the like.More particularly, the processor 1102 may be a complex instruction setcomputing (CISC) microprocessor, a reduced instruction set computing(RISC) microprocessor, a very long instruction word (VLIW)microprocessor, a processor implementing other instruction sets, orother processors implementing a combination of instruction sets. Theprocessor 1102 is configured to execute processing logic in instructionsfor performing the operations and steps discussed herein.

The computer system 1100 may further include a network interface device1110. The computer system 1100 also may or may not include an input1112, configured to receive input and selections to be communicated tothe computer system 1100 when executing instructions. The computersystem 1100 also may or may not include an output 1114, including butnot limited to a display, a video display unit (e.g., a liquid crystaldisplay (LCD) or a cathode ray tube (CRT)), an alphanumeric input device(e.g., a keyboard), and/or a cursor control device (e.g., a mouse).

The computer system 1100 may or may not include a data storage devicethat includes instructions 1116 stored in a computer-readable medium1118. The instructions 1116 may also reside, completely or at leastpartially, within the main memory 1104 and/or within the processor 1102during execution thereof by the computer system 1100, the main memory1104 and the processor 1102 also constituting computer-readable medium.The instructions 1116 may further be transmitted or received over anetwork 1120 via the network interface device 1110.

While the computer-readable medium 1118 is shown in an exemplaryembodiment to be a single medium, the term “computer-readable medium”should be taken to include a single medium or multiple media (e.g., acentralized or distributed database, and/or associated caches andservers) that store the one or more sets of instructions. The term“computer-readable medium” shall also be taken to include any mediumthat is capable of storing, encoding, or carrying a set of instructionsfor execution by the processing device and that cause the processingdevice to perform any one or more of the methodologies of theembodiments disclosed herein. The term “computer-readable medium” shallaccordingly be taken to include, but not be limited to, solid-statememories, optical medium, and magnetic medium.

Note that any of the components disclosed herein can be applied to bothdownlink and/or uplink communication paths in the WDSs disclosed herein.For example, the transmitter (T) side of the HEU 302 in the upperportion of FIG. 5A is in the downlink direction and thus the componentstherein can be for downlink components and be referenced as such. Asanother example, the receiver (R) side of the HEU 302 in the lowerportion of FIG. 5A is in the uplink direction and thus the componentstherein can be uplink components as be referenced as such. As anotherexample, the transmitter (T) side of the RAU 304(1) in the upper portionof FIG. 5B is in the uplink direction and thus the components thereincan be for uplink components and be referenced as such. As anotherexample, the receiver (R) side of the RAU 304(1) in lower portion ofFIG. 5B is in the downlink direction and thus the components therein canbe downlink components as be referenced as such.

The embodiments disclosed herein include various steps. The steps of theembodiments disclosed herein may be formed by hardware components or maybe embodied in machine-executable instructions, which may be used tocause a general-purpose or special-purpose processor programmed with theinstructions to perform the steps. Alternatively, the steps may beperformed by a combination of hardware and software.

The embodiments disclosed herein may be provided as a computer programproduct, or software, that may include a machine-readable medium (orcomputer-readable medium) having stored thereon instructions, which maybe used to program a computer system (or other electronic devices) toperform a process according to the embodiments disclosed herein. Amachine-readable medium includes any mechanism for storing ortransmitting information in a form readable by a machine (e.g., acomputer). For example, a machine-readable medium includes: amachine-readable storage medium (e.g., ROM, random access memory(“RAM”), a magnetic disk storage medium, an optical storage medium,flash memory devices, etc.); and the like.

Unless specifically stated otherwise and as apparent from the previousdiscussion, it is appreciated that throughout the description,discussions utilizing terms such as “processing,” “computing,”“determining,” “displaying,” or the like, refer to the action andprocesses of a computer system, or similar electronic computing device,that manipulates and transforms data and memories represented asphysical (electronic) quantities within the computer system's registersinto other data similarly represented as physical quantities within thecomputer system memories or registers or other such information storage,transmission, or display devices.

The algorithms and displays presented herein are not inherently relatedto any particular computer or other apparatus. Various systems may beused with programs in accordance with the teachings herein, or it mayprove convenient to construct more specialized apparatuses to performthe required method steps. The required structure for a variety of thesesystems will appear from the description above. In addition, theembodiments described herein are not described with reference to anyparticular programming language. It will be appreciated that a varietyof programming languages may be used to implement the teachings of theembodiments as described herein.

Those of skill in the art will further appreciate that the variousillustrative logical blocks, modules, circuits, and algorithms describedin connection with the embodiments disclosed herein may be implementedas electronic hardware, instructions stored in memory or in anothercomputer-readable medium and executed by a processor or other processingdevice, or combinations of both. The components of the distributedantenna systems described herein may be employed in any circuit,hardware component, integrated circuit (IC), or IC chip, as examples.Memory disclosed herein may be any type and size of memory and may beconfigured to store any type of information desired. To clearlyillustrate this interchangeability, various illustrative components,blocks, modules, circuits, and steps have been described above generallyin terms of their functionality. How such functionality is implementeddepends on the particular application, design choices, and/or designconstraints imposed on the overall system. Skilled artisans mayimplement the described functionality in varying ways for eachparticular application, but such implementation decisions should not beinterpreted as causing a departure from the scope of the presentembodiments.

The various illustrative logical blocks, modules, and circuits describedin connection with the embodiments disclosed herein may be implementedor performed with a processor, a Digital Signal Processor (DSP), anApplication Specific Integrated Circuit (ASIC), a Field ProgrammableGate Array (FPGA), or other programmable logic device, a discrete gateor transistor logic, discrete hardware components, or any combinationthereof designed to perform the functions described herein. Furthermore,a controller may be a processor. A processor may be a microprocessor,but in the alternative, the processor may be any conventional processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of computing devices (e.g., a combinationof a DSP and a microprocessor, a plurality of microprocessors, one ormore microprocessors in conjunction with a DSP core, or any other suchconfiguration).

The embodiments disclosed herein may be embodied in hardware and ininstructions that are stored in hardware, and may reside, for example,in RAM, flash memory, ROM, Electrically Programmable ROM (EPROM),Electrically Erasable Programmable ROM (EEPROM), registers, a hard disk,a removable disk, a CD-ROM, or any other form of computer-readablemedium known in the art. An exemplary storage medium is coupled to theprocessor such that the processor can read information from, and writeinformation to, the storage medium. In the alternative, the storagemedium may be integral to the processor. The processor and the storagemedium may reside in an ASIC. The ASIC may reside in a remote station.In the alternative, the processor and the storage medium may reside asdiscrete components in a remote station, base station, or server.

It is also noted that the operational steps described in any of theexemplary embodiments herein are described to provide examples anddiscussion. The operations described may be performed in numerousdifferent sequences other than the illustrated sequences. Furthermore,operations described in a single operational step may actually beperformed in a number of different steps. Additionally, one or moreoperational steps discussed in the exemplary embodiments may becombined. Those of skill in the art will also understand thatinformation and signals may be represented using any of a variety oftechnologies and techniques. For example, data, instructions, commands,information, signals, bits, symbols, and chips, that may be referencesthroughout the above description, may be represented by voltages,currents, electromagnetic waves, magnetic fields, or particles, opticalfields or particles, or any combination thereof.

Unless otherwise expressly stated, it is in no way intended that anymethod set forth herein be construed as requiring that its steps beperformed in a specific order. Accordingly, where a method claim doesnot actually recite an order to be followed by its steps, or it is nototherwise specifically stated in the claims or descriptions that thesteps are to be limited to a specific order, it is in no way intendedthat any particular order be inferred.

It will be apparent to those skilled in the art that variousmodifications and variations can be made without departing from thespirit or scope of the invention. Since modifications, combinations,sub-combinations and variations of the disclosed embodimentsincorporating the spirit and substance of the invention may occur topersons skilled in the art, the invention should be construed to includeeverything within the scope of the appended claims and theirequivalents.

What is claimed is:
 1. A signal distribution unit in a wideband digitalwireless distribution system (WDS), comprising: a transmission analoginput communications interface coupled to a transmission communicationspath, the transmission analog input communications interface configuredto receive, from an analog radio frequency (RF) signal source, atransmission analog RF communications signal having a communicationsbandwidth for a communications service; the transmission communicationspath configured to receive the transmission analog RF communicationssignal from the transmission analog input communications interface, thetransmission communications path comprising: a transmissionanalog-to-digital conversion (ADC) circuit configured to oversample areceived transmission analog RF communications signal at a programmedtransmission oversampling rate of at least twice the highest frequencyin the communications bandwidth to generate a transmission digital RFcommunications signal representing a digitized form of the transmissionanalog RF communications signal; and a transmission programmable digitalsignal processing circuit, comprising: a transmission digital filtercircuit configured to digitally filter the transmission digital RFcommunication signals in a programmed transmission passband into atransmission filtered digital RF communications signal; a transmissiondigital downsampling circuit configured to downsample the transmissionfiltered digital RF communications signals at a programmed transmissiondownsample rate based on the programmed transmission oversampling rateto generate a transmission downsampled digital RF communications signal;a transmission digital output communications interface coupled to thetransmission communications path and at least one transmissioncommunications link coupled to at least one signal receiver unit in theWDS, the transmission digital output communications interface configuredto distribute the transmission downsampled digital RF communicationssignal over the at least one transmission communications link to the atleast one signal receiver unit; a reception digital input communicationsinterface coupled to a reception digital communications path, thereception digital input communications interface configured to receive,from at least one reception communications link, the transmissiondownsampled digital RF communications signal; the reception digitalcommunications path configured to receive a reception digital RFcommunications signal from the reception digital input communicationsinterface, the reception digital communications path comprising: areception programmable digital signal processing circuit, comprising: areception digital upsampling circuit configured to upsample the receivedtransmission downsampled digital RF communications signal at aprogrammed reception upsample rate based on the programmed transmissiondownsample rate to generate a reception upsampled digital RFcommunications signal; and a reception digital filter circuit configuredto digitally filter the reception upsampled digital RF communicationssignals in a programmed reception passband into a reception filteredupsampled digital RF communications signal; and a receptiondigital-to-analog conversion (DAC) circuit configured to convert thereception filtered upsampled digital RF communications signal into areception analog RF communications signal representing an analog form ofthe reception filtered upsampled digital RF communications signal; and areception analog output communications interface coupled to thereception digital communications path, the reception analog outputcommunications interface configured to distribute the reception analogRF communications signal.
 2. The signal distribution unit of claim 1,wherein no filtering circuit is provided in the transmissioncommunications path between the transmission analog input communicationsinterface and the transmission ADC circuit.
 3. The signal distributionunit of claim 1, wherein the transmission communications path furthercomprises a transmission analog front end processing circuitcommunicatively coupled between the transmission analog inputcommunications interface and the transmission ADC circuit, thetransmission analog front end processing circuit comprising a front endfiltering circuit configured to filter the received transmission analogRF communications signal into a transmission filtered analog RFcommunications signal; wherein: the transmission communications path isconfigured to receive the transmission filtered analog RF communicationssignal; and the transmission ADC circuit is configured to oversample thereceived transmission filtered analog RF communications signal at theprogrammed transmission oversampling rate of at least twice the highestfrequency in the communications bandwidth to generate the transmissiondigital RF communications signal representing the digitized form of thetransmission filtered analog RF communications signal.
 4. The signaldistribution unit of claim 1, wherein: the transmission programmabledigital signal processing circuit further comprises a transmissiondigital downlink conversion (DDC) circuit configured to downconvert thefrequency of the transmission digital RF communications signal into atransmission baseband digital RF communications signal; and thetransmission digital filter circuit is configured to digitally filterthe transmission baseband digital RF communications signals in theprogrammed transmission passband into transmission filtered basebanddigital RF communications signal.
 5. The signal distribution unit ofclaim 1, wherein the transmission programmable digital signal processingcircuit further comprises a memory comprising a programmed transmissiondownsample rate entry; and further comprising a controller circuitconfigured to store the programmed transmission downsample rate in theprogrammed transmission downsample rate entry in the memory; thetransmission digital downsampling circuit configured to downsample thetransmission filtered digital RF communications signals at theprogrammed transmission downsample rate stored in the programmedtransmission downsample rate entry to generate the transmissiondownsampled digital RF communications signal.
 6. The signal distributionunit of claim 5, wherein: the memory further comprises a transmissionpassband entry; the controller circuit is further configured to storethe programmed transmission passband in the transmission passband entryin a memory; and the transmission digital filter circuit configured todigitally filter the transmission digital RF communications signals inthe programmed transmission passband stored in the transmission passbandentry into the transmission filtered digital RF communications signal.7. The signal distribution unit of claim 1, wherein the transmissioncommunications path further comprises a programmable digital filteringcircuit communicatively coupled between the transmission analog inputcommunications interface and the transmission ADC circuit, theprogrammable interference filter configured to filter out interferencesignals outside of the programmed transmission passband.
 8. The signaldistribution unit of claim 1, wherein: the at least one transmissioncommunications link is comprised of a plurality of transmissioncommunications links; and further comprising a plurality of thetransmission communication paths coupled to a respective transmissioncommunications link among the plurality of transmission communicationslinks.
 9. The signal distribution unit of claim 8, further comprising aswitch matrix circuit configured to: receive a plurality of transmissiondownsampled digital RF communications signals from the plurality of thetransmission communication paths; and selectively route the plurality oftransmission downsampled digital RF communications signals to at leastone transmission communications link among the plurality of transmissioncommunications links.
 10. The signal distribution unit of claim 1,further comprising: a transmission digital input communicationsinterface coupled to a transmission digital communications path, thetransmission digital input communications interface configured toreceive, from a digital RF signal source, a transmission digital RFcommunications signal; and a second transmission digital outputcommunications interface coupled to the transmission communications pathand the at least one transmission communications link coupled to the atleast one signal receiver unit in the WDS, the second transmissiondigital output communications interface configured to distribute thetransmission digital RF communications signal over the transmissioncommunications link to the at least one signal receiver unit.
 11. Thesignal distribution unit of claim 10, wherein: the at least onetransmission communications link is comprised of a plurality oftransmission communications links; and further comprising a switchmatrix circuit configured to: receive the transmission downsampleddigital RF communications signal from the transmission communicationspath; receive the transmission digital RF communications signal from thetransmission digital communication path; and selectively route thetransmission downsampled digital RF communications signal and thetransmission digital RF communications signal to at least onetransmission communications link among the plurality of transmissioncommunications links.
 12. The signal distribution unit of claim 1,wherein no filtering circuit is provided in the reception digitalcommunications path between the reception analog output communicationsinterface and the reception programmable digital signal processingcircuit.
 13. The signal distribution unit of claim 1, wherein: thereception programmable digital signal processing circuit furthercomprises a reception digital uplink conversion (DUC) circuit configuredto upconvert the frequency of the reception filtered upsampled digitalRF communications signal into a reception digital RF communicationssignal; and the reception DAC circuit configured to convert thereception digital RF communications signal into the reception analog RFcommunications signal representing an analog form of the receptiondigital RF communications signal.
 14. The signal distribution unit ofclaim 1, wherein the reception programmable digital signal processingcircuit further comprises a memory comprising a programmed receptionupsample rate entry; and further comprising a controller circuitconfigured to store the programmed reception upsample rate in theprogrammed reception upsample rate entry in the memory; the receptiondigital upsampling circuit configured to upsample the received receptiondigital RF communications signals at the programmed reception upsamplerate stored in the programmed reception upsample rate entry to generatethe reception upsampled digital RF communications signal.
 15. The signaldistribution unit of claim 14, wherein: the memory further comprises areception passband entry; the controller circuit is further configuredto store the programmed reception passband in the reception passbandentry in the memory; and the reception digital filter circuit configuredto digitally filter the reception upsampled digital RF communicationssignals in the programmed reception passband stored in the receptionpassband entry in the memory into the reception filtered upsampleddigital RF communications signal.
 16. The signal distribution unit ofclaim 1, wherein: the at least one reception communications link iscomprised of a plurality of reception communications links; and furthercomprising a plurality of the reception digital communications pathscoupled to a respective reception communications link among theplurality of reception communications links.
 17. The signal distributionunit of claim 16, further comprising a switch matrix circuit configuredto: receive a plurality of reception digital RF communications signalsfrom the plurality of the reception digital communications paths; andselectively route the plurality of reception digital RF communicationssignals to reception programmable digital signal processing circuits.18. The signal distribution unit of claim 1, further comprising areception digital output communications interface coupled to thereception digital communications path and the at least one receptioncommunications link coupled to a transmission signal unit in the WDS,the reception digital output communications interface configured todistribute the reception digital RF communications signal.
 19. Thesignal distribution unit of claim 18, further comprising a switch matrixcircuit configured to: receive a plurality of reception digital RFcommunications signals from the plurality of the reception digitalcommunications paths; and selectively route the reception digital RFcommunications signals between the reception digital outputcommunications interface and the reception programmable digital signalprocessing circuit.
 20. The signal distribution unit of claim 1comprising a head-end unit, wherein: the transmission communicationspath comprises a downlink transmission communications path; thetransmission analog RF communications signal comprises a downlink analogRF communications signal received from a network; and the at least onesignal receiver unit is comprised of at least one remote antenna unit.21. The signal distribution unit of claim 1 comprising a head-end unit,wherein: the reception digital communications path comprises an uplinkdigital communications path; and the reception digital RF communicationssignal comprises an uplink digital RF communications signal receivedfrom at least one remote antenna unit.
 22. The signal distribution unitof claim 1 comprising a remote antenna unit, wherein: the transmissioncommunications path comprises an uplink transmission communicationspath; the transmission analog RF communications signal comprises anuplink analog RF communications signal received from a client device;and the at least one signal receiver unit is comprised of a head-endunit.
 23. The signal distribution unit of claim 1 comprising a remoteantenna unit, wherein: the reception digital communications pathcomprises a downlink digital communications path; and the receptiondigital RF communications signal comprises a downlink digital RFcommunications signal received from the head-end unit.
 24. A signaldistribution unit in a wideband digital wireless distribution system(WDS), comprising: a transmission analog input communications interfacecoupled to a transmission communications path, the transmission analoginput communications interface configured to receive, from an analogradio frequency (RF) signal source, a transmission analog RFcommunications signal having a communications bandwidth for acommunications service; the transmission communications path configuredto receive the transmission analog RF communications signal from thetransmission analog input communications interface, the transmissioncommunications path comprising: a transmission analog-to-digitalconversion (ADC) circuit configured to oversample a receivedtransmission analog RF communications signal at a programmedtransmission oversampling rate of at least twice the highest frequencyin the communications bandwidth to generate a transmission digital RFcommunications signal representing a digitized form of the transmissionanalog RF communications signal; and a transmission programmable digitalsignal processing circuit, comprising: a transmission digital filtercircuit configured to digitally filter the transmission digital RFcommunication signals in a programmed transmission passband into atransmission filtered digital RF communications signal; a transmissiondigital downsampling circuit configured to downsample the transmissionfiltered digital RF communications signals at a programmed transmissiondownsample rate based on the programmed transmission oversampling rateto generate a transmission downsampled digital RF communications signal;and a transmission digital output communications interface coupled tothe transmission communications path and at least one transmissioncommunications link coupled to at least one signal receiver unit in theWDS, the transmission digital output communications interface configuredto distribute the transmission downsampled digital RF communicationssignal over the at least one transmission communications link to the atleast one signal receiver unit, wherein: the transmission analog inputcommunications interface is configured to receive, from the analog RFsignal source, an electrical transmission analog RF communicationssignal having the communications bandwidth for the communicationsservice; the transmission communications path is configured to receivethe electrical transmission analog RF communications signal from thetransmission analog input communications interface; the transmission ADCcircuit is configured to oversample the received electrical transmissionanalog RF communications signal at the programmed transmissionoversampling rate of at least twice the highest frequency in thecommunications bandwidth to generate an electrical transmission digitalRF communications signal representing the digitized form of theelectrical transmission analog RF communications signal; and thetransmission digital filter circuit is configured to digitally filterthe electrical transmission digital RF communication signals in theprogrammed transmission passband into an electrical transmissionfiltered digital RF communications signal; and the transmission digitaldownsampling circuit is configured to downsample the electricaltransmission filtered digital RF communications signals at theprogrammed transmission downsample rate based on the programmedtransmission oversampling rate to generate an electrical transmissiondownsampled digital RF communications signal; the transmissioncommunications path further comprises an electrical-to-optical (E-O)converter configured to convert the electrical transmission downsampleddigital RF communications signal into an optical transmissiondownsampled digital RF communications signal; the transmission digitaloutput communications interface coupled to the transmissioncommunications path and at least one optical transmission communicationslink coupled to at least one signal receiver unit in the WDS, thetransmission digital output communications interface configured todistribute the optical transmission downsampled digital RFcommunications signal over the at least one optical transmissioncommunications link to the at least one signal receiver unit.
 25. Asignal distribution unit in a wideband digital wireless distributionsystem (WDS), comprising: a transmission analog input communicationsinterface coupled to a transmission communications path, thetransmission analog input communications interface configured toreceive, from an analog radio frequency (RF) signal source, atransmission analog RF communications signal having a communicationsbandwidth for a communications service; the transmission communicationspath configured to receive the transmission analog RF communicationssignal from the transmission analog input communications interface, thetransmission communications path comprising: a transmissionanalog-to-digital conversion (ADC) circuit configured to oversample areceived transmission analog RF communications signal at a programmedtransmission oversampling rate of at least twice the highest frequencyin the communications bandwidth to generate a transmission digital RFcommunications signal representing a digitized form of the transmissionanalog RF communications signal; and a transmission programmable digitalsignal processing circuit, comprising: a transmission digital filtercircuit configured to digitally filter the transmission digital RFcommunication signals in a programmed transmission passband into atransmission filtered digital RF communications signal; a transmissiondigital downsampling circuit configured to downsample the transmissionfiltered digital RF communications signals at a programmed transmissiondownsample rate based on the programmed transmission oversampling rateto generate a transmission downsampled digital RF communications signal;and a transmission digital output communications interface coupled tothe transmission communications path and at least one transmissioncommunications link coupled to at least one signal receiver unit in theWDS, the transmission digital output communications interface configuredto distribute the transmission downsampled digital RF communicationssignal over the at least one transmission communications link to the atleast one signal receiver unit, wherein: the reception digital inputcommunications interface is configured to receive, from the at least onereception communications link comprising at least one optical receptioncommunications link, the optical transmission downsampled digital RFcommunications signal; the reception digital communications path furthercomprises an optical-to-electrical (O-E) converter configured to convertthe optical transmission downsampled digital RF communications signalinto an electrical reception digital RF communications signal; thereception digital communications path is configured to receive theelectrical reception digital RF communications signal from the O-Econverter; the reception digital upsampling circuit is configured toupsample the received electrical reception digital RF communicationssignals at the programmed reception upsample rate based on theprogrammed transmission downsample rate to generate an electricalreception upsampled digital RF communications signal; the receptiondigital filter circuit is configured to digitally filter the electricalreception upsampled digital RF communications signals in the programmedreception passband into an electrical reception filtered upsampleddigital RF communications signal; the reception DAC circuit isconfigured to convert the electrical reception filtered upsampleddigital RF communications signal into an electrical reception analog RFcommunications signal representing an analog form of the electricalreception filtered upsampled digital RF communications signal; and thereception analog output communications interface coupled to thereception digital communications path, the reception analog outputcommunications interface configured to distribute the electricalreception analog RF communications signal.
 26. A method of distributingan analog radio-frequency (RF) communications signal in a wirelessdistribution system (WDS), comprising: receiving from an analog RFsignal source, a transmission analog RF communications signal having acommunications bandwidth for a communications service on a transmissioncommunications path; oversampling the received transmission analog RFcommunications signal in the transmission communications path at aprogrammed transmission oversampling rate of at least twice the highestfrequency in the communications bandwidth to generate a transmissiondigital RF communications signal representing a digitized form of thetransmission analog RF communications signal; digitally filtering thetransmission digital RF communications signal in the transmissioncommunications path in a programmed transmission passband into atransmission filtered digital RF communications signal; downsampling thetransmission filtered digital RF communications signals in thetransmission communications path at a programmed transmission downsamplerate based on the programmed transmission oversampling rate to generatea transmission downsampled digital RF communications signal;distributing the transmission downsampled digital RF communicationssignal from the transmission communications path over at least onetransmission communications link to at least one signal receiver unit;receiving, from at least one reception communications link thetransmission downsampled digital RF communications signal; upsamplingthe received transmission downsampled digital RF communications signalat a programmed reception upsample rate based on the programmedtransmission downsample rate to generate a reception upsampled digitalRF communications signal; digitally filtering the reception upsampleddigital RF communication signals in a programmed reception passband intoa reception filtered upsampled digital RF communications signal;converting the reception filtered upsampled digital RF communicationssignal into a reception analog RF communications signal representing ananalog form of the reception filtered upsampled digital RFcommunications signal; and distributing the reception analog RFcommunications signal.
 27. The method of claim 26, further comprisingnot filtering the transmission communications path before oversamplingthe received transmission analog RF communications signal.
 28. Themethod of claim 26, comprising filtering the received transmissionanalog RF communications signal into a transmission filtered analog RFcommunications signal before oversampling the received transmissionanalog RF communications signal, and comprising: oversampling thereceived transmission filtered analog RF communications signal in thetransmission communications path at the programmed transmissionoversampling rate of at least twice the highest frequency in thecommunications bandwidth to generate the transmission digital RFcommunications signal representing the digitized form of thetransmission analog RF communications signal.
 29. The method of claim28, further comprising amplifying the transmission filtered analog RFcommunications signal into a transmission amplified filtered analog RFcommunications signal, and comprising: oversampling the receivedtransmission amplified filtered analog RF communications signal in thetransmission communications path at the programmed transmissionoversampling rate of at least twice the highest frequency in thecommunications bandwidth to generate the transmission digital RFcommunications signal representing the digitized form of thetransmission analog RF communications signal.
 30. The method of claim29, further comprising downconverting the frequency of the transmissiondigital RF communications signal into a transmission baseband digital RFcommunications signal, and comprising: digitally filtering thetransmission baseband digital RF communications signals in theprogrammed transmission passband into a transmission filtered basebanddigital RF communications signal.
 31. The method of claim 26, furthercomprising storing the programmed transmission downsample rate in aprogrammed transmission downsample rate entry in a memory, andcomprising: downsampling the transmission filtered digital RFcommunications signals at the programmed transmission downsample ratestored in the programmed transmission downsample rate entry to generatethe transmission downsampled digital RF communications signal.
 32. Themethod of claim 30, wherein: further comprising storing the programmedtransmission passband in a passband entry in a memory, and comprising:digitally filtering the transmission digital RF communications signalsin the programmed transmission passband stored in the programmedtransmission downsample rate entry into the transmission filtereddigital RF communications signal.
 33. The method of claim 26, furthercomprising: receiving, from a digital RF signal source, a transmissiondigital RF communications signal; and distributing the transmissiondigital RF communications signal over the at least one transmissioncommunications link to the at least one signal receiver unit.
 34. Thesignal distribution unit of claim 33, further comprising selectivelyrouting the transmission downsampled digital RF communications signaland the transmission digital RF communications signal to the at leastone transmission communications link.
 35. The method of claim 26,further comprising not filtering a received reception digital RFcommunications signals before upsampling the received reception digitalRF communications signals at the programmed reception upsample ratebased on the programmed transmission downsample rate to generate thereception upsampled digital RF communications signal.
 36. The method ofclaim 26, further comprising upconverting the frequency of the receptionfiltered upsampled digital RF communications signal into a receptiondigital RF communications signal, and comprising: converting thereception digital RF communications signal into the reception analog RFcommunications signal representing an analog form of the receptiondigital RF communications signal.
 37. The method of claim 26, furthercomprising storing the programmed reception upsample rate in aprogrammed reception upsample rate entry in a memory, and comprising:upsampling received reception digital RF communications signals at theprogrammed reception upsample rate stored in the programmed receptionupsample rate entry to generate the reception upsampled digital RFcommunications signal.
 38. The method of claim 37, further comprisingstoring the programmed reception passband in a reception passband entryin a memory, and comprising: digitally filtering the reception upsampleddigital RF communications signals in the programmed reception passbandstored in the reception passband entry in the memory into the receptionfiltered upsampled digital RF communications signal.
 39. A wirelessdistribution system (WDS), comprising: a head-end unit, comprising: ahead-end downlink analog input communications interface coupled to ahead-end downlink communications path, the head-end downlink analoginput communications interface configured to receive, from an analogradio frequency (RF) signal source, a downlink analog RF communicationssignal having a communications bandwidth for a communications service;the head-end downlink communications path comprising: a head-enddownlink analog-to-digital conversion (ADC) circuit configured tooversample a received downlink analog RF communications signal at aprogrammed transmission oversampling rate of at least twice the highestfrequency in the communications bandwidth to generate a downlink digitalRF communications signal representing a digitized form of the downlinkanalog RF communications signal; and a head-end transmissionprogrammable digital signal processing circuit, comprising: a head-enddownlink digital filter circuit configured to digitally filter thedownlink digital RF communications signals in a programmed transmissionpassband into a downlink filtered digital RF communications signal; ahead-end downlink digital downsampling circuit configured to downsamplethe downlink filtered digital RF communications signals at a programmedtransmission downsample rate based on the programmed transmissionoversampling rate to generate a downlink downsampled digital RFcommunications signal; and a head-end downlink digital outputcommunications interface coupled to the head-end downlink communicationspath and at least one transmission communications link coupled to atleast one signal receiver unit in the WDS, the head-end downlink digitaloutput communications interface configured to distribute the downlinkdownsampled digital RF communications signal over the at least onedownlink communications link to at least one remote antenna unit among aplurality of remote antenna units; and the at least one remote antennaunit among the plurality of remote antenna units comprises: a remotedownlink digital input communications interface coupled to a remotedownlink digital communications path, the remote downlink digital inputcommunications interface configured to receive, from the at least onedownlink communications link, the downlink downsampled digital RFcommunications signal; the remote downlink digital communications pathcomprising: a remote downlink programmable digital signal processingcircuit, comprising: a remote downlink digital upsampling circuitconfigured to upsample the received downlink digital RF communicationssignals at a programmed reception upsample rate based on the programmedtransmission downsample rate to generate a downlink upsampled digital RFcommunications signal; and a remote downlink digital filter circuitconfigured to digitally filter the downlink upsampled digital RFcommunication signals in a programmed reception passband into a downlinkfiltered upsampled digital RF communications signal; a remote downlinkdigital-to-analog conversion (DAC) circuit configured to convert thedownlink filtered upsampled digital RF communications signal into thedownlink analog RF communications signal representing an analog form ofthe downlink filtered upsampled digital RF communications signal; and aremote downlink analog output communications interface configured todistribute the downlink analog RF communications signal to a clientdevice.
 40. The WDS of claim 39, wherein: the at least one remote unitfurther comprises: a remote uplink analog input communications interfaceconfigured to receive a downlink analog RF communications signal havinga communications bandwidth for a communications service from a clientdevice; a remote uplink analog communications path comprising: a remoteuplink ADC circuit configured to oversample a received uplink analog RFcommunications signal at a programmed transmission oversampling rate ofat least twice the highest frequency in the communications bandwidth togenerate an uplink digital RF communications signal representing adigitized form of the uplink analog RF communications signal; and aremote uplink transmission programmable digital signal processingcircuit, comprising: a remote uplink digital filter circuit configuredto digitally filter the uplink digital RF communications signals in aprogrammed transmission passband into an uplink filtered digital RFcommunications signal; a remote uplink digital downsampling circuitconfigured to downsample the uplink filtered digital RF communicationssignals at a programmed transmission downsample rate based on theprogrammed transmission oversampling rate to generate an uplinkdownsampled digital RF communications signal; and a remote uplinkdigital output communications interface coupled to at least one uplinkcommunications link, the remote uplink digital output communicationsinterface configured to distribute the uplink downsampled digital RFcommunications signal over the at least one uplink communications linkto the head-end unit; and the head-end unit further comprises: ahead-end uplink digital input communications interface coupled to ahead-end uplink digital communications path, the head-end uplink digitalinput communications interface configured to receive, from the at leastone remote unit over the at least one uplink communications link, theuplink downsampled digital RF communications signal; the head-end uplinkdigital communications path comprising: a head-end uplink programmabledigital signal processing circuit, comprising: a head-end uplink digitalupsampling circuit configured to upsample the received uplinkdownsampled digital RF communications signal at the programmed receptionupsample rate based on the programmed transmission downsample rate togenerate an uplink upsampled digital RF communications signal; and ahead-end uplink digital filter circuit configured to digitally filterthe uplink upsampled digital RF communications signals in a programmedreception passband into an uplink filtered upsampled digital RFcommunications signal; a head-end uplink digital-to-analog conversion(DAC) circuit configured to convert the uplink filtered upsampleddigital RF communications signal into the uplink analog RFcommunications signal representing an analog form of the uplink filteredupsampled digital RF communications signal; and a head-end uplink analogoutput communications interface configured to distribute the uplinkanalog RF communications signal over the at least one uplinkcommunications link to an analog RF signal source.